Caption: PROPERTY RELEASED. MODEL RELEASED. Paediatric examination. Doctor checking a 7-year-old boy's glands to see if they are swollen. Swelling of the glands (lymphadenopathy) is very common in children and can be caused by a minor infection. The glands, or lymph nodes, are part of the body's immune system and contain white blood cells that attack invading micro-organisms. During an infection the glands enlarge as they become more active, producing warm, tender lumps that can be felt under the skin around the neck.